id,summary,reporter,owner,description,type,status,priority,milestone,component,version,severity,resolution,keywords,cc,lang,patch,platform
1155,dynext - dll versioning,rurban,,"Thanks to the Windows DLL Hell L<http://en.wikipedia.org/wiki/DLL_hell> 
and the impossibility of file hardlinks, windows dll names are hopefully 
versioned, so either the loadlib function or the various pir's needs 
more logic for maintainance convenience.

Keep the lib_paths and share_ext search, add more name munging for 
special platforms.

Either
1) add the version to each loadlib call, and stem the version from
POSIX versions within get_path().

loadlib lib, 'libSDL-1.2.so.0'

=> try: libSDL-1.2.so.0, libSDL-1.2.so

stemmed: libSDL.so
on WIN32: SDL-1.2.dll, SDL.dll
on cygwin: cygSDL-1.2.dll, cygSDL.dll

Maybe also detect the ""-1.2.so.0"" and convert it to ""-1.2.0.dll""

2) add an optional version argument to loadlib. (preferred)

loadlib lib, 'SDL', '1.2.0'

=> Try: first always prefix with ""lib""
libSDL-1.2.0.so, libSDL-1.2.so.0, libSDL-1.2.so, libSDL.so
other rules stay as they are. (lib_paths + share_ext)
on WIN32: no lib prefix and try versions.
SDL-1-2-0.dll, SDL-1-2.dll, SDL-1.2.0.dll, SDL-1.2.dll, SDL.dll
on cygwin: cyg prefix and try versions with '.' and '-'.
cygSDL-1.2.dll, cygSDL-1.2.0.dll, cygSDL-1-2-0.dll, cygSDL-1-2.dll

All the pir's for the latest packaged libraries are fixed with RT#51328.

RT#51328 also applies the addional lib => cyg dll logic, but does not 
help with versioned dll's, as for ncurses and SDL most prominently.

Examples what we want to avoid:

loadlib $P1, 'libform'
+if $P1 goto has_lib
+loadlib $P1, 'cygform-8'
+has_lib:

loadlib $P1, 'libncurses'
+if $P1 goto has_lib1
+loadlib $P1, 'cygncurses-8'
+has_lib1:

# third try
loadlib libsdl, 'libSDL-1.2.so.0'

+ loadlib libsdl, 'cygSDL-1-2-0'
+ $I0 = typeof libsdl
+ if $I0 != .Undef goto OK

loadlib image_lib, 'libSDL_image-1.2.so.0'
$I0 = typeof image_lib
if $I0 != .Undef goto OK_HINT2

+ loadlib image_lib, 'cygSDL_image-1-2-0'
+ $I0 = typeof image_lib
+ if $I0 != .Undef goto OK
+

See also other ffi's, such as cffi, how they do deal or not with this 
problem. Years ago I wrote an overview at 
http://autocad.xarch.at/lisp/ffis.html
-- 
Reini Urban
http://phpwiki.org/ http://murbreak.at/
http://helsinki.at/ http://spacemovie.mur.at/",todo,new,normal,,none,,medium,,,,,,